Improved self-centering chuck



aanvalt and I do hereby declare that the following is f of the same.

UNITED STATES L Partitur` DFFICE.

EDGAR Il. BEACH, OF TEST MERIDEN, CONNlOTlCUT.

Specification forming part cfLettcrs Patent No. 114.067, dated September 6, 1864. I

To all whom, it mag/concern:

Be it known that I, EDGAR B. BEACH, of West Meridemin the county ot' New Haven and State of Connecticut, have invented a newand Improved Self-Centering Chuck;

a inll, clear, and exact description thereof', which will enable those skilled in the art to makeand use the saine, reference being had to the accompanying drawings, forming part of this specification, in which- Figure l represents a longitudinal central section of my invention. Fig. 2 is an end view Similar letters of reference indicate correspending paris.

This invention consists in the use ot' three (more or less) inclined or converging guide ways in combination with the jaws of the chuck, to which a longitudinally-sliding motion is imparted by a central screw or other suitable means in such a manner that said jaws, on heilig t'orced out in'the converging guideways, will contract concentrically and clamp an article placed between them and hold it firmly and in the true center of the lathespindle to which said chuck isattachcd.

Arepresents a screw-spindle, which forms the guide for the head B of my' chuck. This screw-spindle is boredrout at one end andl fitted on a conical plug, C, which is inserted into the lathe-spindle in the ordinary manner; orisaid screw-spindle may be secured to the lathe-spindle in any other suitable manner. Great care must be taken, however, to secure said screw-spindle so that it runs perfectly true, and that it can readily be taken on" and reattached without ruiming out of truth. The head B is provided at its inner end with an internal screw-thread, b, which screws over' the corresponding male thread, a, ot thespindle A, and the outer end of said head is tapering and provided with three (more orz less) converging guideways, c', in which the jaws U vmove in and out. These jaws are. placed into the gnidewa-ys from the outside, andthey are prevented from dropping oiif by a cap, D, which screws on the head B. This cap is tapering to correspond to the converging outer edges ot the jaws, so that if a small article is placed in the chuck it can be reached with the tool close up to the jaws C with more convenience than it couldv if the cap should be made cylindrical throughout. The inner edges of the jaws are parallel with and equidistantfroin the central axis of the chuck, and they are provided with notches d, which catch over a collar, e, secured to and projecting from the extreme end of the screwspindle A. Y

It' a drill, tap,or other smaller articleis tobe inserted into this chuck, the jaws are opened by turning the .head B out, and after the article has been entered between the jaws the head B is turned in on the screw-spindle, whereby thejaws close up and clamp the article tight. The inner edges of thejaws move in and out perfectly concentric, so that an article placed between them will always be in the ce'nterand no centering is required.

This chuck is applicable in turning small articles or in drilling or cutting screws, and it is of very great convenience, since by its aid a drill or tap or other tool can be readily cen tered in the lathe without loss of time, and articles to be turned can be convenienti).r reached withl the tool, `the'outside ot' my chuck being perfectly smooth and its point tapering so that the danger .of being caught in a screw or other projection is obviated, and the articles to be turned can be worked ott' quick and with little loss ot' time.

I claim as new and desire to secure by Letters Patent- A The inclined converging guif-,leways c, vin combination with the jaws C. head B, and screw-spindle A, constructed and opera-ting in the manner and for the purpose substantially as herein shown and described.

EDGAR B. BEACH.

Wit ncsscs: JOHN S. CLARK, CHARLES N.' H Anm. 

